Splitting and Merging

Splitting

SS - split cells dialog box

SS before split > SS after split

Merging

To merge two existing cells highlight them and select (Table > Merge Cells) or use the buttom from the Tables and Borders toolbar.
SS - icon

All the text from the selected cells will be comboned with a carriage return between each cell entry.
The new cell will be the total width of all the previous cells.
The widths of any of the other columns or cells will not be affected.

SS before merge > SS after merge